The most relevant prior art is to be found in European patent application No. 109,921 in which other oxadiazolyl derivatives of imidazobenzodiazepines are disclosed. The compounds are described as being able to displace flunitrazepam from benzodiazepine receptors.
European patent application No. 150,040 also discloses oxadiazolyl derivatives of imidazobenzodiazepines. Although the generic claims of that patent application include compounds having the general formula II ##STR3## wherein R.sup.3, R.sup.4, R.sup.5, and R.sup.A have meanings as defined below, this European patent application No. 150,040 does not disclose any examples of compounds wherein R.sup.A is alkoxy or lower alkyl.